Are you using Online TurboTax or desktop software (CD/download)?
If Online TurboTax, what edition--Free, Deluxe, Premier, etc.?
To enter data for a Form 8949, you go through the Investment Income interview to report investment sales, which will prepare Schedule D and Form 8949, if needed.
We can tell you how to get there once we know what you're using. Also, what are you trying to report--do you have a Form 1099-B?
